Have to say my 2004 Cummins would only "roll coal" if I were babing it then stuck my foot in her. Then only for a very very short time, other then that she burned very clean.
I agree at what cost has all of this emission garbage cost us? My 04 could hit the same mileage that my Ecodiesel does 27+ all day long on the highway @ 77 MPH for the ED and 70 for the Cummins. What are these new 6.7 diesels making, maybe 20 MPG @ 60 MPH if your lucky?
Nope the reason we have these emissions are first and foremost big trucks sitting in rest stops, truck stops or where ever idling for hours on end. 10 years ago if you drove past any truck stop or rest stop you had to do it holding your breath and drive through the diesel fog! The second were buses spewing black diesel exhaust out the tailpipe! The third and not near as much were the clowns thinking they are cool cranking their tuners up and pumping black smoke going through intersections or where ever.
Don